Biomedical subjects

K Kadipasaoglu

Publications and source records attributed to K Kadipasaoglu.

5 recordsLinked to original sources

PubMed2001

Online detection of myocardial ischemia by near infrared spectroscopy with a fiberoptic catheter.

BACKGROUND: The interruption of myocardial O2-supply in acute myocardial ischemia causes differences in coronary venous O2-content. In this study, the oxygenation status of coronary sinus blood is detected in myocardial ischemia by near infrared (NIR) spectroscopy. METHOD: For the intravascular application, a new fiberoptic catheter is developed. After calibration of the catheter by perfusion of blood with standardized gas mixtures in an in vitro experiment, the in vivo application was performed in 12 domestic pigs. The catheter was placed into coronary sinus and an anterior ischemia was induced by temporary occlusion of LAD. NIR graphs and hemodynamic data were obtained for 90 min ischemia and 90 min reperfusion time. RESULTS: Main NIR-spectroscopic differences between oxygenated and de-oxygenated hemoglobin took place in O2-concentrations less than 30%. Coronary sinus NIR spectra of hemoglobin-oxygen binding showed significant, reproducible differences between pre-ischemia, LAD-occlusion and reperfusion. NIR graphs also show variations related to CO2-concentration, pH and temperature. CONCLUSION: The intravascular application of NIR spectroscopy could be a reliable tool in detection and follow-up of acute myocardial ischemia and infarction.

Animals↗

PubMed2001

[Intravascular detection of myocardial ischemia by spectrometry in the near infrared spectrum in experimental animals].

Interruption of oxygen supply in acute myocardial ischaemia reduces venous return of oxygen at the coronary sinus. In this study, the oxygen content of venous return in the coronary sinus was measured by using spectrometry in the near infrared spectrum. The authors developed a new intravascular catheter made of fibre optics. After in vitro calibration by blood flow based on a standard gas mixture used in in vitro experiment, an in vivo application in 12 domestic pigs was undertaken. The catheter was positioned in the coronary sinus and ischaemia induced by temporary occlusion of the left anterior descending artery. Recordings of the near infrared spectrum and haemodynamic data were obtained during 90 minutes' ischaemia followed by 90 minutes reperfusion. Spectrometry in the near infrared range detected a marked difference between oxyhaemoglobin and deoxyhaemoglobin, especially when the oxygen concentration was less than 30%. The near infrared spectrum of liaison between haemoglobin and oxygen in the coronary sinus shows significant and reproducible differences between pre-ischaemia occlusion of the left anterior descending artery and reperfusion. The recordings of the near infrared also show variation in CO2, pH and temperature. The authors conclude that the use of intravascular spectrometry of the near infrared spectrum could be a permanent reliable tool for detection and follow-up of acute myocardial ischaemia.

Animals↗

PubMed1997

Transmyocardial laser revascularization: results of a multicenter trial with transmyocardial laser revascularization used as sole therapy for end-stage coronary artery disease.

BACKGROUND: Transmyocardial laser revascularization was used as the sole therapy for patients with ischemic heart disease not amenable to percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. This technique uses a carbon dioxide laser to create transmyocardial channels for direct perfusion of the ischemic heart. METHODS: Since 1992, 200 patients, at eight hospitals in the United States, have undergone transmyocardial laser revascularization. The patients have a combined 1560 months of follow-up for an average of 10 +/- 3 months per patient. Their age was 63 +/- 10 years and their ejection fraction was 47% +/- 12%. Eighty-two percent had at least one previous bypass graft operation and 38% had a prior angioplasty. Preoperatively, the patients underwent nuclear single photon emission computed tomography perfusion scans to identify the extent and severity of their ischemia. These scans were repeated at 3, 6, and 12 months. Angina class, admissions for angina, and medications were recorded. RESULTS: The perioperative mortality was 9%. Angina class decreased significantly from before treatment to 3, 6, and 12 months (p < 0.001). Likewise, there was a significant decrease in the number of perfusion defects in the treated left ventricular free wall. Concomitantly, there was a significant decrease in the number of admissions for angina in the year after the procedure when compared with the year before treatment (2.5 vs 0.5 admissions per patient-year). CONCLUSION: These combined results indicate that transmyocardial laser revascularization provides angina relief, decreases hospital admissions, and improves perfusion in patients with severe coronary artery disease.

Adult↗

PubMed1997

Revascularization procedures in patients with transplant coronary artery disease.

OBJECTIVE: To assess the efficacy of revascularization in cardiac transplant patients who developed de novo coronary artery disease. METHODS: Eighteen patients underwent one or more of four methods of revascularization: percutaneous transluminal coronary angioplasty (PTCA), percutaneous transluminal coronary rotational atherectomy (PTCRA), coronary artery bypass grafting (CABG), and transmyocardial laser revacularization (TMLR). Eleven PTCA procedures were performed in 10 patients 55.3 +/- 6.6 months after transplantation. Six patients underwent PTCRA 83.3 +/- 11.2 months after transplantation. Five patients underwent CABG 54.0 +/- 12.6 months after transplantation; the mean left ventricular ejection fraction was 49.6 +/- 16.9 (20-65%); hypertrophy was present in two of these patients. One patient with distal coronary artery disease and New York Heart Association class IV symptoms underwent TMLR only. One patient underwent both CABG and TMLR because of triple vessel proximal disease, diffuse distal disease, and New York Heart Association class IV symptoms. RESULTS: PTCA was successful in 10 procedures with decrease in mean stenosis from 87.7 +/- 2.7 to 24.3 +/- 6.0%. Follow-up, at 16.9 +/- 4.0 months, showed restenosis in two patients. PTCRA was successful in all patients with a decrease in mean stenosis from 83.4 +/- 4.4 to 11.7 +/- 1.9%. Short-term follow-up did not reveal reocclusion. Two CABG patients who had hypertrophy died of heart failure 2 and 9 days after their operations. One CABG patient with excellent cardiac function died after 15 days because of pulmonary failure. In one patient, left ventricular ejection fraction improved from 35 to 50%, and he is alive 64 months later. Six months after TMLR, the New York Heart Association class in one patient improved from IV to II, and his left ventricular ejection fraction improved from 29 to 42%. The ejection fraction in the patient who underwent both CABG and TMLR improved from 20 to 56% but the patient expired 7 weeks later. CONCLUSIONS: It appears that revascularization procedures can be effective in patients with coronary artery disease after cardiac transplantation and that coronary angioplasty or atherectomy would be a therapy of choice for single proximal lesions. CABG should be used cautiously and only reserved for patients with multi-vessel disease without hypertrophy. Laser revascularization with or without bypass grafting has potential to become the therapy of choice for transplant coronary artery disease.

Angioplasty, Balloon, Coronary↗

PubMed1996

Transmyocardial laser revascularization.

Transmyocardial laser revascularization is currently being tested in randomized clinical trials as an alternative technique for relieving angina in patients with ischemic myocardium. In this technique, an 800-W carbon dioxide laser is used to create channels in the myocardium that open directly into the left ventricular cavity. Although the exact mechanism by which tissue revascularization occurs is not yet known, initial results from an earlier clinical trial were promising: a significant number of patients were relieved of angina symptoms, exercise tolerance was improved, complications were minimal, and the safety of the technique seems established. A controlled, randomized trial is now underway, and initial results appear promising.

Female↗